Keyboard shortcuts for "Straighten" in iPhoto?

If you've used iPhoto for photo retouching, you probably know the Straighten functionality.

My question is, are there any keyboard shortcuts for rotating the photo, or is mouse & the slider the only way? Any other useful tips regarding this are of course also welcome.

It can be somewhat slow and awkward to do this with mouse/trackpad for each photo (especially if your mouse is not the most accurate one, like my Logitech bluetooth mouse). In iPhoto '09 they made matters worse by removing the small buttons next to the slider that you could click to rotate by one step (0.1 degrees).

Solution 1:

You can press the S key to activate the straighten tool. And the return key will save any changes. Unfortunately, I am not sure how to control the slider in order to actually make a change using the keyboard.